01 - Rub salt and black pepper evenly over all sides of the beef short ribs.
02 - In a large skillet over medium-high heat, brown the short ribs on each side for 2 to 3 minutes. Transfer browned ribs to the slow cooker.
03 - Add onion, carrots, celery, and minced garlic to the same skillet. Sauté for 3 to 4 minutes until beginning to soften. Transfer vegetables to the slow cooker.
04 - Pour beef broth and red wine into the slow cooker. Stir in tomato paste and Worcestershire sauce until incorporated.
05 - Place thyme sprigs, rosemary sprigs, and bay leaves into the slow cooker.
06 - Cover and cook on LOW setting for 8 hours, until ribs are exceptionally tender and the meat easily separates from the bone.
07 - Remove thyme, rosemary sprigs, and bay leaves. Skim any excess surface fat as needed.
08 - If a thicker sauce is desired, mix cornstarch with water and stir into the slow cooker. Set to HIGH and cook for 10 to 15 minutes until the sauce has thickened.
09 - Arrange hot short ribs with sauce and vegetables on plates and serve immediately.